The instant invention relates to a device for attachment to the top rungs of a ladder to stabilize the ladder against a vertical surface and maintain tools and supplies within easy reach of the user.
Ladders placed against a wall have always posed a stability problem. The problem is more serious when the ladder must be used on a corner or near a window where there is often insufficient surface on which to support the rails. A variety of devices have been developed that have attempted to solve this problem.
In U.S. Pat. No. 2,327,317 Randall teaches a hollow frame to be attached by means of brackets to the rails of a ladder. An independent arm extends outward from each side of the hollow frame as needed. Angled portions attached to the arms make contact with the wall. A second embodiment provides straight portions extending forward from the arms at right angles. Each of the straight portions can be extended as far as needed and independent of the other so that the ladder can be stabilized against an irregular wall. This same arrangement can be used at the bottom of the ladder to stabilize it on irregular ground. The ends of the contacting parts may be pointed or have rubber feet to prevent slippage. Similar devices are taught by Werner (U.S. Pat. No. 3,568,801), Wing (U.S. Pat. No. 4,502,566) and Southern (U.S. Pat. No. 5,113,973). None of these devices can be used at corners of intersecting walls.
In U.S. Pat. No. 6,152,262, Jung discloses stabilizing bars that are stored within one hollow rung of a ladder. The bars can extend from the ladder at an angle and are composed of telescoping segments that can be locked in place to extend as far as needed. Additional supporting members can also be stored within another rung of the ladder. This invention cannot be adapted to surfaces that are not flat.
Burk teaches a U-shaped brace that is attached at the top of a ladder. The arms of the U extend forward and make contact with the wall. Rubber grips at the ends of the arms prevent slipping. A cross bar adds strength and a chain extending from the cross bar to another rung provides additional support. Sockets mounted on the inside of each arm at a 45xc2x0 angle can accept additional extension arms by threading into the sockets. These extensions enable the brace to stabilize the ladder on an outside corner by gripping the wall on each side of the outside corner. (U.S. Pat. No. 2,592,006) Another U-shaped brace for use on a ladder provides additions for insertion at the end of each forward extending arm. The additions have ends that are turned inward at a 45xc2x0 angle and covered with rubber sleeves for the support of the ladder on an outside corner. (Peters, U.S. Pat. No. 3,072,218) Neither of these devices are horizontally adjustable and therefore are of limited use around windows or other structures within the wall.
Brewer et al. in U.S. Pat. No. 4,593,790, disclose a foldable device to be attached to a ladder for stability. The device can be folded into several orientations so the ladder can be stabilized at an outside corner, an inside corner, an overhang and can be set to span a window. Spring loaded hinges enable the various configurations. This device is quite complex and appears cumbersome and heavy.
In U.S. Pat. No. 3,693,756, Walker et al. teach a U-shaped brace that can be attached to the top of a ladder with arms extending forward for stability against a wall and to the bottom of a ladder with arms extending downward for stability on the ground. A compartment for holding supplies can be attached to the brace as can hooks for such things as paint cans. The brace is of fixed dimensions and so is of limited use. Terwilliger (U.S. Pat. No. 3,146,854) discloses a ladder positioning attachment that consists of an upper plate and a lower plate with a centralized separator in between. The plates extend forward of and beyond the sides of the ladder. The portion of the attachment that lies between the rails is bolted to a rung. On each side of the device a leg is pivotally attached between the plates. There are several holes through the upper plate and another hole in each leg. The legs can be moved into several positions and set in place by inserting a fastener through the selected hole in the plate and the hole in the leg. As the angle of the legs change, so does the distance of the upper part of the ladder from the wall. Tools or other objects can be set on the flat upper plate. This device is only usable against a flat wall.
None of the prior art devices provide stability for a ladder at all wall variations and also provide means to hold tools and supplies. None of the prior art provides a means to keep small objects such as nails and screws close at hand and easy to reach. And none of the prior art patents teach the technology that will enable a ladder to be stabilized against a column or tree. There is a need for a device that can be attached to the top of any ladder and accomplish all of these tasks.
The present invention provides a stabilizing means for attachment to a ladder to enable the ladder to be set securely against a variety of vertical surfaces and also provides means to hold numerous tools and supplies within easy reach.
It is an object of the present invention to provide a stabilizer that can be easily and securely attached to any straight ladder.
It is another object of the present invention to provide a stabilizer for ladders that prevents the ladder from slipping once set in place whether against a flat wall or corner.
A further object of the present invention is to provide a stabilizer for ladders that can be used against most vertical surfaces and can span various structural variations such as windows and corners.
A still further object of the present invention is to provide a stabilizer for ladders that can hold a ladder securely against a tree or column.
Another object of the present invention is to provide a stabilizer that can also hold tools and supplies, including small objects such as screws and nails, so they are within easy reach.
A further object of the present invention is to provide a stabilizer that can quickly and easily be adapted from one type of vertical surface to another.
A still further object of the present invention is to provide a stabilizer that is inexpensive to manufacture and can be manufactured using readily available materials.
Another object of the present invention is to provide a stabilizer that can be quickly fastened securely to the ladder and can easily be removed therefrom
A still further object of the present invention is to provide a stabilizer with parts that fit within the framework for compact storage and easy transport.
The instant invention is a stabilizer for supporting a ladder of a type having parallel side rails and a series of transverse rungs set at regular intervals therebetween against a substantially vertical surface. The stabilizer comprises a tubular frame comprising a first rearward frame member fixedly attached longitudinally to a second forward frame member, and two angled frame members affixed near the center of the forward frame member at opposing acute angles thereto and lying in the same plane with the first and second frame members. There are two sleeves pivotally attached to the underside of the frame with a tension spring connecting the two sleeves. Two support arms, a rearward support arm and a forward support arm, are dimensioned to fit slidably and reversibly within the first frame member, the second frame member, the angled frame members and the sleeves. Each support arm is bent to form a leg extending at a right angle therefrom. Attachment means are affixed to the tubular frame for reversibly attaching the stabilizer to the ladder.